Powder inhaler devices

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to facilitating release of powder contained in a receptacle. More specifically, the present invention relates to the administration of medication by a method and apparatus for facilitating inhalation of powder medicaments.

2. Related Art

In the medical field, it is often desirable to administer various forms of medication to patients. Well known methods of introducing medication into the human body include the oral ingestion of capsules and tablets, intravenous injection through hypodermic needles, and numerous others. In one method, certain medications may be inhaled into a patient's respiratory tract and lungs through the nose or mouth. Certain of these medications, such as bronchodilators, corticosteroids, etc., for the treatment of asthma and other respiratory anomalies, may be aimed at the respiratory tract directly. Others are inhaled for purposes of systemic treatment, i.e. for treatment of any area of the body through absorption from the respiratory tract through the lung tissue, into the deep lungs, and into the bloodstream. Each of these medications comes in a variety of forms, including fluids, which are commonly administered as an aerosol vapor or mist, as well as solids. Inhalable solids typically take the form of fine, dry powders. Specialized devices, such as inhalers, are provided to assist the patient in directing these fine powder medications into the respiratory tract.

Various types of inhalers are known for the administration of dry powder medicaments. However, each of these inhalers suffers certain drawbacks. For example, U.S. Pat. No. 5,787,881 discloses an inhaler that is used with encapsulated dry powder medicaments. However, use of this device requires numerous steps and imposes a number of inconveniences on a user. For example, the medication capsules used with the device have an aperture formed therein prior to insertion into an opening in the inhaler. Therefore, there exists a danger that an amount of medication may be lost prior to or during insertion into the device. After insertion of the capsule, use of the device requires the additional step that a cover must be closed before the medication may be inhaled.

Inhalation devices configured for use with a capsule containing some type of medicament are shown in U.S. Pat. No. 4,069,819 to Valentini et al. (“the '819 patent”) and U.S. Pat. No. 4,995,385 to Valentini et al. (“the '385 patent”). The inhalation device described in the '385 patent was developed to overcome the drawbacks of the device described in the '819 patent. Particularly, in a large number of cases, the device described in the '819 patent experienced irregular and incomplete emptying of the capsule, thereby resulting in difficulties in properly administering the medicament in the capsule. The inhalation device described in the '385 patent attempts to overcome this deficiency by tapering the nebulization chamber toward the end surface that comprises the discharge holes. Thus, the nebulization chamber of the '385 patent is not cylindrical, but rather frusto-conical in form in an attempt to achieve regular complete emptying of the nebulization chamber.

However, further improvements in the design of inhalation devices are needed to achieve high emitted doses and highly dispersed powders while maintaining low resistance, especially when the inhaler is used with high doses and is operated at low peak inspiratory flow rates (PIFR) and low inhalation volumes. As used herein, “emitted dose” (ED) refers to the percentage of the dose of powder medicament that is emitted from a receptacle in the inhalation device. The dispersal of the powder can be quantified by measuring the volume mean geometric diameter (VMGD) of the emitted powder. As used herein “volume mean geometric diameter” refers to the average geometric diameter of the powder. As used herein, “resistance” refers to the square root of the pressure gradient across the inhaler divided by the peak inspiratory flow rate through the inhaler. As used herein “low peak inspiratory flow rate” refers to a peak inspiratory flow rate of approximately 25 L/min or less. Moreover, improvements are needed to achieve high emitted doses and highly dispersed powders that are consistently reproducible, i.e., that have a low standard deviation of emitted dose percentage and VMGD, respectively.

U.S. Pat. Nos. 6,766,799 and 6,732,732, which are assigned to the same entity as the one to which the current application is under an obligation of assignment, disclose further improvements over previously known devices. These patents disclose, among other things, a ring that is circumferentially coupled to the inside of a chamber for receiving the medicament capsule. Such a ring is intended to improve the reproducibility of the emitted dose during operation of the device. The patents also disclose staples of differing configurations for puncturing the receptacle during operation of the device.

Another drawback of the inhalation devices described in the '819 and the '385 patents is the piercing device that is used to puncture the capsule. Such conventional piercing devices are formed from circular stock, with the points created by pinching the stock at an angle, thereby creating a single sharp cutting edge. Drawbacks of such a design are that the point (which must puncture the capsule material) is often rounded, lessening its effectiveness as a piercing device. Moreover, burrs often form on the lower edge, which can stop the piercing device from retracting from the capsule, thereby causing a device failure. The holes formed by such a conventional piercing device are generally round, and do not have the appearance of being cut by a sharp edge. With such a conventional design, the capsule is often crushed, rather than punctured or pierced. If such a conventional piercing device is used with brittle capsule materials such as gelatin, pieces of capsule material of a size that can be inhaled are usually broken off from the capsule. Thus, conventional piercing devices are less than optimal, particularly for brittle capsule material.

The co-owned '799 and '732 patents additionally disclose staples of differing configurations and prongs for puncturing the receptacle during operation of the device. These configurations are intended to improve the operation of the inhalation device. These patents also disclose means for indicating when the powder in the inhaler is ready for inhalation by the user, which is a useful improvement over devices previously known before the '799 and '732 patents.

There is a need, however, for further improvements of such inhalation devices. Namely, there is a need for reliable attachment of the staple for puncturing the capsule or receptacle to the rest of the device, considering the repetitive use and forceful impacts that the staple-device attachment undergoes during operation. In addition, there is a need to reduce or eliminate the possibility of external dust and grime from entering and adversely affecting the operation of the device during periods of non-use, as well as periods of use. Additionally, there is a need to prevent inadvertent and unintentional operation of the device, which might occur when components of the device are subjected to random forces that trigger its operation without the volition of the user. Finally, there is a need for reducing undesired air flow into the inhaler device at its rest position, which has an adverse impact on the effectiveness of the device.

Thus, there is a need in the art for an improved method and apparatus for facilitating inhalation of dry powder medicaments. What is needed is an inhaler that provides for reliable and robust attachment of the staple, that prevents dust and grime from entering into the device and prevents unintentional operation of the device, and that reduces undesired air flow in to the inhaler device at its rest position.

SUMMARY OF THE INVENTION

In one embodiment of the invention, an inhalation device for administering a dose of powder contained in a receptacle is provided. The inhalation device includes a first casing portion and a second casing portion movably coupled to the first casing portion. The second casing portion includes a mouthpiece portion and a chamber configured to hold the receptacle. A plunger is coupled to the first casing portion, movably coupled to the second casing portion, and additionally includes a notched end. The inhaler device includes a hook member that is coupled to the plunger in a manner that secures a substantially U-shaped staple to the plunger.

In another embodiment of the invention, the plunger of the inhalation device has a substantially flat surface and includes at least one projecting portion that projects from the flat surface. The at least one projecting portion swagingly secures a U-shaped staple to the plunger.

In yet another embodiment of the invention, the base of the staple of the inhaler device has a thick cross section relative to the tines of the staple. One of the base and the plunger has at least one flange, and the other has at least one corresponding projecting hook which is configured to receive the at least one flange.

In yet another embodiment of the invention, at least one tine is secured to the distal end of the plunger by injection molding the at least one tine in a volume of space within the distal end of the plunger.

Another embodiment of the invention provides for sealable coupling of the first casing portion and the body portion of an inhalation device in a rest position of the inhalation device. In this embodiment, an end of one of the first casing portion and the body portion has a radially projecting portion around its circumference, and an end of the other of the two has a concave cross section. Further, the radially projecting portion has a convex cross section. The coupling of the concave and convex portions substantially provides a seal when the inhalation device is in its rest position.

Another embodiment of the invention also provides for sealable coupling of the first casing portion and the body portion of an inhalation device in a rest position of the inhalation device. In this embodiment, an insert element is receivably coupled to one of the first casing portion and the body portion. The insert element forms a closed curve substantially normal to an axis of substantial symmetry of at least one of the first casing portion and the body portion. The insert element is sealably coupled to both the first casing portion and the body portion in a rest position of the inhalation device.

Another embodiment of the invention provides a cap that encloses the second casing portion when the cap is engaged to the inhalation device, and additionally prevents the movement of the first casing portion of the inhalation device with respect to the second casing portion.

BRIEF DESCRIPTION OF THE FIGURES

The present invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements.

<figref idrefs="DRAWINGS">FIG. 1</figref> is a front view of one embodiment of an inhaler device that may be used with embodiments of the present invention.

<figref idrefs="DRAWINGS">FIG. 2</figref> is a cross-sectional view of the inhaler device of <figref idrefs="DRAWINGS">FIG. 1</figref> taken along a plane parallel to an axis of substantial symmetry of the device.

<figref idrefs="DRAWINGS">FIG. 3A</figref> is a side view of the distal end of a plunger in accordance with an embodiment of the invention.

<figref idrefs="DRAWINGS">FIG. 3B</figref> is a view in perspective of the distal end of the plunger of <figref idrefs="DRAWINGS">FIG. 3A</figref>.

<figref idrefs="DRAWINGS">FIG. 3C</figref> is a top view of the distal end of the plunger of <figref idrefs="DRAWINGS">FIG. 3A</figref>.

<figref idrefs="DRAWINGS">FIG. 4A</figref> is a view in perspective of a plunger in accordance with another embodiment of the invention.

<figref idrefs="DRAWINGS">FIG. 4B</figref> is a view in perspective of the plunger in accordance with the embodiment of <figref idrefs="DRAWINGS">FIG. 4A</figref> in which a U-shaped staple is attached to an end of the plunger.

<figref idrefs="DRAWINGS">FIG. 5A</figref> is a view in perspective of a staple and plunger in accordance with yet another embodiment of the invention.

<figref idrefs="DRAWINGS">FIG. 5B</figref> is a side view of the staple and plunger of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

<figref idrefs="DRAWINGS">FIG. 5C</figref> is a cross-sectional view of the staple and plunger of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

<figref idrefs="DRAWINGS">FIG. 5D</figref> is a view in perspective of an alternate embodiment of the staple and plunger of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

<figref idrefs="DRAWINGS">FIG. 5E</figref> is an enlarged view of the plunger of the embodiment of <figref idrefs="DRAWINGS">FIG. 5D</figref> without the staple.

<figref idrefs="DRAWINGS">FIG. 5F</figref> is a cross-sectional view of an alternate embodiment of the plunger of <figref idrefs="DRAWINGS">FIG. 5D</figref> that has a staple assembly that includes a single tine.

<figref idrefs="DRAWINGS">FIG. 6A</figref> is a cross-sectional view of another embodiment of a staple and plunger in accordance with the invention.

<figref idrefs="DRAWINGS">FIG. 6B</figref> is a view in perspective of the staple and plunger of the embodiment of <figref idrefs="DRAWINGS">FIG. 6A</figref>.

<figref idrefs="DRAWINGS">FIG. 6C</figref> is a side view of the staple and plunger of the embodiment of <figref idrefs="DRAWINGS">FIG. 6A</figref>.

<figref idrefs="DRAWINGS">FIG. 7A</figref> is a view of an inhaler without the mouthpiece portion attached.

<figref idrefs="DRAWINGS">FIG. 7B</figref> is two side views of the inhaler of <figref idrefs="DRAWINGS">FIG. 7A</figref> with the mouthpiece portion attached.

<figref idrefs="DRAWINGS">FIG. 7C</figref> is a view of a cap in accordance with an embodiment of the invention.

<figref idrefs="DRAWINGS">FIG. 7D</figref> is two side views of the cap of <figref idrefs="DRAWINGS">FIG. 7C</figref> secured to an inhaler device.

<figref idrefs="DRAWINGS">FIG. 8A</figref> is two side views of an alternate embodiment of the cap of <figref idrefs="DRAWINGS">FIG. 7C</figref> that is secured to an inhaler device.

<figref idrefs="DRAWINGS">FIG. 8B</figref> is two side views of yet another alternate embodiment of the cap of <figref idrefs="DRAWINGS">FIG. 7C</figref> that is secured to an inhaler device.

<figref idrefs="DRAWINGS">FIG. 9A</figref> is a view of an inhaler device in accordance with an embodiment of the invention in which the body portion and the first casing portion of the inhaler device are sealably coupled at a rest position of the device.

<figref idrefs="DRAWINGS">FIG. 9B</figref> is an enlarged view of the sealable coupling of <figref idrefs="DRAWINGS">FIG. 9A</figref>.

<figref idrefs="DRAWINGS">FIG. 10A</figref> is a view of an alternate embodiment of the invention in which the body portion and the first casing portion of the inhaler device are sealably coupled at a rest position of the device through an insert element.

<figref idrefs="DRAWINGS">FIG. 10B</figref> is an enlarged view of the insert element of <figref idrefs="DRAWINGS">FIG. 10A</figref>.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Overview

The present invention provides an improved method and apparatus for facilitating release of powder. In a preferred embodiment, the powder is contained in a receptacle. As used herein, the term “receptacle” includes but is not limited to, for example, a capsule, blister, film covered container well, chamber, and other suitable means of storing a powder known to those skilled in the art. The present invention will be described below in the context of a method and apparatus for dispensing dry powder medicaments for inhalation by a patient. However, it should be apparent to one skilled in the art that the invention is not limited to such an exemplary embodiment, and could be used for other purposes.

The methods of the present invention use an inhaler to dispense powder by inhalation. In embodiments of the invention, a user operates the device to puncture the receptacle to disperse powder in the chamber, and inhales the powder through the inhalation portion.

As used herein, “attachment” and “coupling” are intended to cover embodiments in which two pieces are removably or irremovably attached to one another, as well as embodiments in which the two pieces are fused or permanently attached to one another.

Inhaler and Associated Method of the Present Invention

A front view of one embodiment of an inhalation device <b>100</b> is shown in <figref idrefs="DRAWINGS">FIG. 1</figref>. The rear view of device <b>100</b> is substantially identical to the front view. Device <b>100</b> includes a first or lower casing portion <b>120</b> and a second or upper casing portion <b>130</b> removably coupled to first casing portion <b>120</b>. Upper casing portion <b>130</b> and lower casing portion <b>120</b> include a flattened region <b>132</b> and <b>122</b>, respectively, for ease of gripping the casing for use by a patient. Lower casing portion <b>120</b> preferably includes an outer casing <b>126</b> and an inner casing <b>124</b> movably received within outer casing <b>126</b>. A removable cap <b>110</b> as shown in <figref idrefs="DRAWINGS">FIG. 1</figref> may be provided at the user or inhalation end of the device.

Preferred materials for device <b>100</b> include Food and Drug Administration (FDA) approved, USP tested plastics. Preferably, device <b>100</b> is manufactured using an injection molding process, the details of which would be readily apparent to one skilled in the art.

<figref idrefs="DRAWINGS">FIG. 2</figref> is a cross-section of device <b>100</b> taken along a plane that is parallel to the axis of substantial symmetry of device <b>100</b>. As shown in <figref idrefs="DRAWINGS">FIG. 2</figref>, device <b>100</b> includes an inhalation or emitter portion <b>220</b>. Inhalation portion <b>220</b> comprises a hemispheric region <b>222</b> that defines a plurality of apertures <b>224</b>. It should be understood that the present invention is not limited to a particular number of apertures <b>224</b>, and can be configured such that at least one aperture <b>224</b> is provided. An inhalation piece <b>226</b> is provided to allow for inhalation of the medicament by a user. Inhalation piece <b>226</b> can be configured as a mouth piece for inhalation through a user's mouth. Alternatively, inhalation piece <b>226</b> can be configured as a nose piece for inhalation through a user's nose. For purposes of this application, “mouthpiece” shall denote mouth pieces for inhalation through a user's mouth and nose pieces for inhalation through a user's nose, as well as other possibilities such as a piece for insertion in or on a tracheotomy tube in a patient undergoing, or who has had, a tracheotomy.

Device <b>100</b> includes a cylindrical chamber <b>210</b> that is defined by a straight wall <b>212</b> of circular cross-section. Chamber <b>210</b> has a proximal end <b>214</b> and a distal end <b>216</b>. A plurality of vents <b>218</b> are defined by wall <b>212</b>, and are configured for introducing air into chamber <b>210</b> to disperse powder released from a capsule <b>219</b>. It should be understood that the present invention is not limited to a particular number of vents <b>218</b>, and can be configured such that at least one vent <b>218</b> is provided. Powder released from capsule <b>219</b> is dispersed in chamber <b>210</b> and inhaled through apertures <b>224</b> and inhalation piece <b>226</b> by the user.

In other embodiments of the invention, receptacles other than capsules are used, such as blisters and film covered container wells as is known in the art. In one embodiment, the volume of the receptacle is at least about 0.37 cm³. In another embodiment, the volume of the receptacle is at least about 0.48 cm³. In yet another embodiment, the receptacles have a volume of at least about 0.67 cm³or 0.95 cm³. In one embodiment of the invention, the receptacle is a capsule designated with a capsule size 2, 1, 0, 00, or 000. Suitable capsules can be obtained, for example, from Shionogi (Rockville, Md.). Blisters can be obtained, for example, from Hueck Foils, (Wall, N.J.).

The receptacle encloses or stores particles, also referred to herein as powders. The receptacle is filled with particles in a manner known to one skilled in the art. For example, vacuum filling or tamping technologies may be used. Generally, filling the receptacle with powder can be carried out by methods known in the art. In one embodiment of the invention, the particle or powder enclosed or stored in the receptacle have a mass of at least about 5 milligrams (mg). In another embodiment, the mass of the particles stored or enclosed in the receptacle is at least about 10 mg, and up to approximately 50 mg. In a preferred embodiment, the mass of the particles is approximately 20 mg.

In one embodiment of the present invention, particles used with the device have a tap density of less than about 0.4 g/cm³. Particles having a tap density of less than about 0.4 g/cm³are referred to herein as “aerodynamically light”. In a preferred embodiment, the particles have a tap density of near to or less than about 0.1 g/cm³. Tap density is a measure of the envelope mass density characterizing a particle. The envelope mass density of particles of a statistically isotropic shape is defined as the mass of the particle divided by the minimum sphere envelope volume within which it can be enclosed. Features that can contribute to low tap density include irregular surface texture and hollow or porous structure. Particularly preferred particles and powders are described in U.S. Pat. Nos. 6,136,295, 5,985,309, 5,874,064, 5,855,913 and 6,858,199, filed Jun. 9, 2000 entitled “High Efficient Delivery of a Large Therapeutic Mass Aerosol”, the entirety of each of the foregoing patents and patent applications is hereby incorporated herein by reference.

Device <b>100</b> includes a staple assembly <b>230</b> that is used to puncture capsule <b>219</b> to release powder contained therein into chamber <b>210</b>. In the embodiment shown in <figref idrefs="DRAWINGS">FIG. 2</figref>, staple assembly <b>230</b> includes at one end a substantially U-shaped staple <b>232</b> that has two prongs. In this embodiment, each of the prongs of U-shaped staple <b>232</b> is configured with a square cross-section <b>234</b>, thereby providing a sharp point and two cutting edges.

Previously known staple assemblies for puncturing a receptacle or capsule in inhaler devices include prongs (or tines) that have wide, broad surfaces that are intended as puncturing edges. Although such staple assemblies may be used with embodiments of the invention, more effective puncturing of the receptacle may be achieved using staple assemblies with prongs that have sharp points. Wide broad surfaces require greater force to puncture a rounded surface such as a capsule, causing the capsule to buckle in an undesirable way. Staple assemblies that have prongs with sharp points for puncturing, as disclosed, for example, in U.S. patent application Ser. No. 10/771,551, which is assigned to the same entity to which the present application is under an obligation of assignment, do not present such problems. For that reason, preferred embodiments of the invention, as disclosed below, utilize staple assemblies that have prongs with sharp puncturing points.

The inhaler of the present invention is preferably configured with a staple assembly for puncturing the receptacle that improves puncturing performance, particularly with brittle receptacle material. In one preferred embodiment, the staple assembly for puncturing the receptacle of the present invention includes as a substantially U-shaped staple that is attached to a plunger, with each of the two prongs of the U-shaped staple having a sharp point and two cutting edges. In one such embodiment, each prong has a square cross-section, with the staple material being bent around a face so that the innermost part of the U-shaped staple is flat. In another such embodiment, the staple material is rotated 45 degrees so that it is bent around an edge so that the innermost part of the U-shaped staple is an edge. In such an embodiment, the end surface of each prong is an angled diamond-shaped surface.

In another preferred embodiment, the staple assembly for puncturing the receptacle is configured as a substantially longitudinal prong that is attached to a plunger, with the prong comprising a puncturing surface on the distal end, a primary cutting surface running from the proximal end to the distal end of the prong and terminating at the puncturing surface, and a substantially planar face opposite to the primary cutting edge and running from the proximal end to the distal end of the prong. The prong preferably has an angled surface at the distal end, the angled surface having a distal end terminating at the puncturing surface and a proximal end terminating at the substantially planar face. In addition, the prong is preferably tapered so that the distal end is smaller than the proximal end, to facilitate removing the prong from a receptacle. The prong also preferably has a plurality of longitudinal faces and a plurality of longitudinal edges running from the proximal end to the distal end of the prong.

The prong is configured to create an opening in a wall by forming a hanging chad in the wall, the hanging chad having a free end formed by the puncturing surface and the primary cutting edge and a hinge coupled to the wall formed by the face. In a preferred embodiment, the prong is configured to open the hanging chad to an angle of at least 30 to 45 degrees between the minor axis of the receptacle and the hanging chad, wherein the minor axis is substantially perpendicular to a longitudinal axis of the receptacle, which is substantially parallel to the longitudinal prong.

Other embodiments of staple assemblies for puncturing a capsule are disclosed and discussed in U.S. Pat. Nos. 6,766,799 and 6,732,732, which are herein incorporated by reference in their entirety.

Staple assembly <b>230</b> is preferably configured to be movable between a non-puncturing position (as depicted in <figref idrefs="DRAWINGS">FIG. 1</figref>) and a puncturing position. In the puncturing position, prongs <b>232</b> pierce or puncture capsule <b>219</b> to make holes therein. In a preferred embodiment, a means for biasing is provided that biases staple assembly <b>230</b> in the non-puncturing position. In the embodiment shown in <figref idrefs="DRAWINGS">FIG. 2</figref>, the means for biasing is configured as a spring <b>242</b> that biases the substantially U-shaped staple (and staple assembly <b>230</b> to which it is attached) in the non-puncturing position.

As noted with respect to <figref idrefs="DRAWINGS">FIG. 1</figref>, device <b>100</b> includes inner casing <b>124</b> and outer casing <b>126</b>. As shown in <figref idrefs="DRAWINGS">FIG. 2</figref>, a spring <b>244</b> is disposed in lower casing portion <b>120</b> that biases inner casing <b>124</b> in an outward position. Upon compression of spring <b>244</b>, inner casing <b>124</b> moves from the outward position to an inward position, thereby drawing lower casing portion <b>120</b> toward upper casing portion <b>130</b>. Compression of spring <b>244</b> also causes compression of spring <b>242</b>, thereby causing staple assembly <b>230</b> to move to the puncturing position. Upon release of compression, springs <b>242</b> and <b>244</b> return to their biased state, thereby returning staple assembly <b>230</b> to its non-puncturing position, and inner casing <b>124</b> to its outward position.

A pair of flanges <b>252</b> is disposed on first casing portion <b>120</b>. A pair of grooves <b>254</b> is disposed on second casing portion <b>130</b> so that flanges <b>252</b> can be received within grooves <b>254</b> to thereby couple the first and second casing portions. Preferably, the first and second casing portions are coupled with a friction-fit engagement. A friction-fit engagement can be achieved using the groove and flange arrangement depicted in <figref idrefs="DRAWINGS">FIG. 2</figref>. Other alternative configurations for a friction-fit engagement would be readily apparent to one skilled in the art.

In the inhaler of <figref idrefs="DRAWINGS">FIG. 2</figref>, staple <b>232</b> is one part of the single piece that is the staple assembly <b>230</b>. In certain embodiments of the current invention, the staple assembly comprises at least two parts, a staple and a plunger, with the staple attached at the distal end of the plunger. <figref idrefs="DRAWINGS">FIGS. 3A</figref>, <b>3</b>B and <b>3</b>C show the distal end <b>310</b> of plunger <b>395</b> of staple assembly <b>230</b>, in a first such embodiment of the present invention. The term “distal end”, when used in reference to the plunger, denotes the end of the plunger that is furthest from the first casing portion (i.e., the end that is nearest the mouth or nose of the user when the device is in operation.) <figref idrefs="DRAWINGS">FIG. 3A</figref> illustrates distal end <b>310</b> of this embodiment in profile, with the line of sight substantially perpendicular to each of the axes of substantial symmetry of plunger <b>395</b> and distal end <b>310</b>. <figref idrefs="DRAWINGS">FIG. 3B</figref> illustrates distal end <b>310</b> in perspective, from a line of sight forming an obtuse angle with these axes. <figref idrefs="DRAWINGS">FIG. 3C</figref> shows a view of distal end <b>310</b> looking down along the axes of plunger <b>395</b> and distal end <b>310</b>. In this embodiment, distal end <b>310</b> is formed to contain notch <b>330</b>, which provides the space in which the means for the staple attachment and the staple are situated. In this embodiment, hook <b>320</b>, which is attached to distal end <b>310</b> and functions as the means for attaching a staple to distal end <b>310</b>, is configured to fix a staple (not shown in <figref idrefs="DRAWINGS">FIG. 3</figref> but similar, for example, to U-shaped staple <b>490</b> of <figref idrefs="DRAWINGS">FIG. 4B</figref>) to distal end <b>310</b> by compression of the staple between hook <b>320</b> and distal end <b>310</b>. In the configuration in which the staple is attached to the distal end <b>310</b>, the bottom of the U-part of the staple threads through slot <b>350</b>, which is formed from a gap between hook <b>320</b> and distal end <b>310</b>. In an aspect of this embodiment (shown in <figref idrefs="DRAWINGS">FIG. 3A</figref>), grooves <b>340</b>, located substantially diametrically opposed from one another along a cross section of distal end <b>310</b>, provide support for the sides of the U-shaped staple, which provides further compressive support in fixing the U-shaped staple to distal end <b>310</b>. The staple and hook <b>320</b> may be fixed onto distal end <b>310</b> during manufacture of plunger <b>232</b> through, for example, injection molding, in a manner that will be apparent to those of skill in the art. In preferred embodiment, hook <b>320</b> is made from the same material as distal end <b>310</b>, and is fused by injection molding onto it.

<figref idrefs="DRAWINGS">FIGS. 4A and 4B</figref> show another embodiment of staple assemblies in accordance with the invention, in which a staple, for example, the U-shaped staple <b>490</b> of <figref idrefs="DRAWINGS">FIG. 4B</figref>, is swagingly secured to distal end <b>410</b> of plunger <b>495</b>. <figref idrefs="DRAWINGS">FIG. 4A</figref> illustrates plunger <b>495</b> in the configuration before attachment of U-shaped staple <b>490</b>. Here, plunger <b>495</b> contains one or more projecting portions <b>420</b> that project substantially perpendicularly from a surface of distal end <b>410</b>, which in the embodiment illustrated in <figref idrefs="DRAWINGS">FIG. 4A</figref> is substantially flat. Projecting portions <b>420</b> in <figref idrefs="DRAWINGS">FIG. 4A</figref> are arranged circumferentially around portion <b>430</b> of distal end <b>410</b>, which is configured to receive the staple. In other aspects of this embodiment, any number of similar projecting portions may be present, each located either circumferentially within or around portion <b>430</b>. Portion <b>430</b> may contain one or more grooves <b>435</b> as shown in <figref idrefs="DRAWINGS">FIG. 4A</figref> that are shaped to receive the staple; such a configuration may provide better slippage-free attachment of the staple to distal end <b>410</b>. Further, as shown in the embodiment of <figref idrefs="DRAWINGS">FIG. 4A</figref>, distal end <b>410</b> may additionally include a retaining projecting portion <b>445</b> that is used for vertical retention of plunger <b>495</b>.

<figref idrefs="DRAWINGS">FIG. 4B</figref> illustrates plunger <b>495</b> in a configuration in which U-shaped staple <b>490</b> has been swagingly secured to distal end <b>410</b>. During the swaging process, projecting portions <b>420</b>, which in this embodiment are made from plastic, are heated and swaged down to compress U-shaped staple <b>490</b> against the substantially flat surface of distal end <b>410</b> into a fixed configuration. Upon cooling of the swaged projecting portions <b>420</b>, U-shaped staple <b>490</b> is fixed to distal end <b>410</b> as shown in <figref idrefs="DRAWINGS">FIG. 4B</figref>. Retaining projecting portion <b>445</b> of this embodiment is not swaged and remains in a projecting configuration, as depicted in <figref idrefs="DRAWINGS">FIG. 4B</figref>.

<figref idrefs="DRAWINGS">FIGS. 5A through 5F</figref> show another embodiment of a staple assembly in accordance with the invention in which the staple includes a thick base that is movably received within hooks projecting from the sides of the distal end of the plunger. <figref idrefs="DRAWINGS">FIG. 5A</figref> illustrates distal end <b>510</b>, with staple <b>530</b> mounted thereon, in perspective, from a line of sight forming an obtuse angle with the axis of substantial symmetry of distal end <b>510</b>. <figref idrefs="DRAWINGS">FIG. 5B</figref> shows the same configuration in profile, with the line of sight substantially perpendicular to that axis. <figref idrefs="DRAWINGS">FIG. 5C</figref> shows a cross section of the same configuration taken along a plane that is parallel to the axis of distal end <b>510</b>. In this embodiment staple <b>530</b> comprises a thick base <b>540</b> and one or more tines <b>550</b> that provide the puncturing functionality. Distal end <b>510</b> includes projecting hooks <b>520</b> that project from distal end <b>510</b>. In the embodiment shown in <figref idrefs="DRAWINGS">FIG. 5A</figref>, two such projecting hooks are present, each diametrically opposed to the other. These hooks provide rails through which corresponding flanges at the base of thick base <b>540</b> (not shown) are movably received; preferably, the combination is configured to provide friction-fitted engagement. Attachment of staple <b>530</b> to distal end <b>510</b> is provided in this way in the embodiment shown in <figref idrefs="DRAWINGS">FIGS. 5A-5C</figref>. Alternatively, securable attachment of staple <b>530</b> to distal end <b>510</b> may be provided by, for example, including a groove (or rib) at a predetermined location along the inner surface of projecting hook(s) <b>520</b>, and a corresponding rib (or groove) on the surface of the flange(s) at the base of thick base <b>540</b> (not shown). Such a groove (or rib) on the inner surface of projecting hook(s) <b>520</b> corresponds to the rib (or groove) on the surface(s) of the flange at the base of thick base <b>540</b>, allowing staple <b>530</b> to snap into a securably attached configuration within projecting hooks <b>520</b> of distal end <b>510</b>. Other means for securably attaching staple <b>530</b> to distal end <b>510</b> will be apparent to those of skill in the art based on the present disclosure.

<figref idrefs="DRAWINGS">FIG. 5D</figref> shows another version of the thick-based staple embodiment of <figref idrefs="DRAWINGS">FIGS. 5A-5C</figref>. In this embodiment, projecting hooks <b>520</b> of distal end <b>510</b> include a perpendicular member <b>525</b> that provides support and a greater compressive force for increasing the effectiveness of the friction-fitting engagement of projecting hooks <b>520</b> with the corresponding flanges at the base of thick base <b>540</b>. Perpendicular member <b>525</b> also increases the strength and durability of projecting hooks <b>520</b>. In this embodiment, the extension of the perpendicular member <b>525</b> beyond the upper surface of projecting hooks <b>520</b> is for the purpose of interacting with an adjacent part (not shown) to limit the load and/or impulse applied directly to staple <b>530</b>; any such load or impulse is transferred to perpendicular member <b>525</b>, thereby limiting the stresses applied to projecting hooks <b>520</b> by staple <b>530</b>. This increases the durability of the design of this embodiment.

<figref idrefs="DRAWINGS">FIG. 5E</figref> shows only distal end <b>510</b> (including projecting hooks <b>520</b> and perpendicular member <b>525</b>) of the embodiment of <figref idrefs="DRAWINGS">FIG. 5D</figref> without staple <b>530</b> attached thereon. <figref idrefs="DRAWINGS">FIG. 5F</figref> shows an embodiment that is similar to the embodiment of <figref idrefs="DRAWINGS">FIGS. 5D and 5E</figref> in which only a single tine (tine <b>550</b>) is present on staple <b>530</b>.

<figref idrefs="DRAWINGS">FIGS. 6A-6C</figref> illustrate yet another embodiment of a staple assembly in accordance with the present invention in which one or more tines are insert molded onto the distal end of the plunger. <figref idrefs="DRAWINGS">FIG. 6A</figref> shows a cross section of plunger <b>695</b> of this embodiment, including distal end <b>610</b> and tines <b>650</b>, taken along a plane that is parallel to the axis of substantial symmetry of plunger <b>695</b>. In this embodiment, distal end <b>610</b> of plunger <b>695</b> has a cylindrical shape that provides a cylindrical volume <b>630</b> in which the bases of one or more tines <b>650</b> (i.e., prongs) are secured by injection molding of plastic within the cylindrical volume.

In this embodiment, the base of cylindrical volume <b>630</b> is bounded by a cylindrical plate <b>615</b>, which provides separation of the injected-molded plastic within cylindrical volume <b>630</b> from the rest of the interior of distal end <b>610</b>.

<figref idrefs="DRAWINGS">FIG. 6B</figref> illustrates the embodiment of <figref idrefs="DRAWINGS">FIG. 6A</figref> in perspective, from a line of sight that forms an obtuse angle with the axis of substantial symmetry of distal end <b>610</b>. Similarly, <figref idrefs="DRAWINGS">FIG. 6C</figref> illustrates the same embodiment in profile, with the line of sight substantially perpendicular to the axis of distal end <b>510</b>.

<figref idrefs="DRAWINGS">FIGS. 7C and 7D</figref> illustrate another embodiment of the present invention in which a cap is provided over the inhaler device of <figref idrefs="DRAWINGS">FIGS. 7A and 7B</figref> in a manner that prevents dust and grime from entering into the device. The cap additionally prevents inadvertent and unintentional operation of the device, which might occur when components of the device are subjected to random forces that trigger its operation without the volition of the user.

<figref idrefs="DRAWINGS">FIGS. 7A and 7B</figref> illustrate an inhaler device, for example, similar to the inhaler devices disclosed in U.S. Pat. Nos. 6,766,799 and 6,732,732. The inhaler device of <figref idrefs="DRAWINGS">FIGS. 7A and 7B</figref> comprises first casing portion <b>710</b> that is movably coupled to second casing portion <b>720</b>. Second casing portion <b>720</b> comprises mouthpiece portion <b>725</b> and body portion <b>730</b>. Body portion <b>730</b> includes vents <b>740</b> on its distal end, similar to and having the same functionality of vents <b>218</b> of <figref idrefs="DRAWINGS">FIG. 2</figref>. The inhalation device of <figref idrefs="DRAWINGS">FIGS. 7A and 7B</figref> may contain additional components, such as a staple assembly for puncturing and a capsule containing a dry-powder medicament, for example, as illustrated in <figref idrefs="DRAWINGS">FIG. 2</figref>, or in accordance with any other embodiment of staple assemblies of the invention. The inhaler device of <figref idrefs="DRAWINGS">FIGS. 7A and 7B</figref> is operated by compressing first casing portion <b>710</b> against second casing portion <b>720</b>, which causes a staple attached to the spring-loaded plunger to pierce the capsule. The user may simultaneously or shortly thereafter inhale the dry-powder medicament through mouthpiece portion <b>725</b>, which provides a path for flow for the medicament from the pierced capsule through vents <b>740</b> to the user's mouth.

<figref idrefs="DRAWINGS">FIGS. 7C and 7D</figref> illustrate a cap in accordance with one embodiment of the current invention for use with inhalers similar to the inhaler device of <figref idrefs="DRAWINGS">FIGS. 7A and 7B</figref>. Cap <b>750</b>, as illustrated in <figref idrefs="DRAWINGS">FIG. 7D</figref>, may be placed on the inhaler device in a configuration in which it encloses second casing portion <b>720</b> and is securably attached to first casing portion <b>710</b>. Cap <b>750</b> may be securably attached to first casing portion <b>710</b> in any way that will be apparent to one of ordinary skill in the art based on the present disclosure; for example, an approximately circular rib <b>755</b> (or groove) (see <figref idrefs="DRAWINGS">FIG. 7C</figref>) may be formed within the internal surface of cap <b>750</b> along the circumference of the intersection of a plane substantially perpendicular to the axis of substantial symmetry of cap <b>750</b> with cap <b>750</b>. Similarly, a corresponding approximately circular groove (or rib) may be formed on the outer surface of first casing portion <b>710</b>. Thus, cap <b>750</b> may be securably attached to first casing portion <b>710</b> by a snapping action, which causes the approximately circular rib <b>755</b> to move into place within the corresponding approximately circular groove.

When cap <b>750</b> is securably attached to first casing portion <b>710</b> as shown in <figref idrefs="DRAWINGS">FIG. 7D</figref>, the probability of dust and grime entering into the inhaler is reduced, because in this configuration cap <b>750</b> encloses mouthpiece portion <b>725</b> as well as body portion <b>730</b> of second casing portion <b>720</b>. Further, because operation of the inhaler device is caused by pushing first casing portion <b>710</b> against second casing portion <b>720</b>, and because the presence of cap <b>750</b> on the inhaler device in a securably attached configuration prevents or reduces relative motion of first casing portion <b>710</b> with respect to second casing portion <b>720</b>, cap <b>750</b> in the securably attached configuration also prevents inadvertent operation of the inhaler device by the application of random forces to the device during periods when it is not in use.

<figref idrefs="DRAWINGS">FIGS. 8A and 8B</figref> depict other example embodiments of the cap of the present invention. The inhaler of <figref idrefs="DRAWINGS">FIG. 8A</figref> has a cap <b>850</b> that encloses all of the second casing portion (not shown) and that is coupled to first casing portion <b>810</b> in the inhaler device's closed position in a manner so that cap <b>850</b> only encloses a substantially small amount of the surface area of first casing portion <b>810</b>. The inhaler of <figref idrefs="DRAWINGS">FIG. 8B</figref> has a cap <b>890</b> that encloses all of the second casing portion (not shown), and is coupled to first casing portion <b>860</b> in the inhaler device's closed position in a manner so that cap <b>890</b> substantially does not enclose any of the surface area of first casing portion <b>860</b>. In this embodiment, when the inhaler device is in its closed position with cap <b>890</b> secured, the edges of the open end of cap <b>890</b> sit flush against the edges of the open end of first casing portion <b>860</b>. Securable attachment of cap <b>890</b> to first casing portion <b>860</b> may be achieved through a snapping mechanism in this embodiment, for example, by placing a corresponding rib-groove pair along these edges of cap <b>890</b> and first casing portion <b>860</b>.

<figref idrefs="DRAWINGS">FIGS. 9A and 9B</figref> show another embodiment of the present invention that reduces undesired air flow into the inhaler device at its rest position by providing a substantially air-tight seal between the first casing portion and the body portion at that position. <figref idrefs="DRAWINGS">FIG. 9A</figref> illustrates, in cross-sectional profile, an inhaler device in accordance with this embodiment that is in its rest position. The inhaler device of <figref idrefs="DRAWINGS">FIG. 9A</figref> may, for example, have substantially similar components to the inhaler device of <figref idrefs="DRAWINGS">FIG. 2</figref> (or an inhaler device in accordance with any other embodiment of the invention), such as first casing portion <b>910</b>, second casing portion <b>920</b> (including mouthpiece portion <b>925</b> and body portion <b>930</b>), plunger <b>995</b> and chamber <b>945</b>. In this embodiment, corresponding structures at each of the distal ends of first casing portion <b>910</b> and body portion <b>930</b> are sealably coupled at the rest position of the inhaler device. Portion <b>990</b> of the inhaler device of <figref idrefs="DRAWINGS">FIG. 9A</figref> is shown in exploded view and greater detail in <figref idrefs="DRAWINGS">FIG. 9B</figref>. In this embodiment, body portion <b>930</b> at its distal end and outer surface has a radially projecting portion <b>970</b>. The cross-section of the tip of radially projecting portion <b>970</b> forms a convex curve, as shown in <figref idrefs="DRAWINGS">FIG. 9B</figref>. The corresponding portion <b>960</b> of first casing portion <b>910</b> that is coupled to the tip of radially projecting portion <b>970</b> at the rest position of the inhaler device forms a concave curve, as shown in <figref idrefs="DRAWINGS">FIG. 9B</figref>. The convex tip of projecting portion <b>970</b> and the corresponding portion <b>960</b> are shaped correspondingly so that they contact one another along a finite surface area of each. A substantially air-tight seal may result from the contact of such corresponding portions in such a manner; in particular, the biasing force of the springs in plunger <b>995</b> in the embodiment of <figref idrefs="DRAWINGS">FIGS. 9A and 9B</figref> causes these corresponding portions to push against one another, which results in a frictional seal.

Other embodiments for achieving such a substantially air-tight seal will be apparent to those with ordinary skill in the art based on the present disclosure. For example, in an embodiment that is the converse of the embodiment of <figref idrefs="DRAWINGS">FIGS. 9A and 9B</figref>, first casing portion <b>910</b> may have a projecting portion that forms, in cross section, a convex curve on at its distal end and on its inner surface, whereas body portion <b>930</b> at the corresponding position at its distal end and outer surface may form, in cross section, a corresponding concave curve. These components, which will be in contact at the rest position of the inhaler device of this embodiment, may once again form a substantially air-tight seal. In the embodiments of <figref idrefs="DRAWINGS">FIGS. 9A and 9B</figref> and its variations, the curves are preferably smooth curves, in that tangents to each curve are well-defined at all points along the curve. In other embodiments, the curves are smooth only along sections of contact of body portion <b>930</b> and first casing portion <b>910</b>.

<figref idrefs="DRAWINGS">FIGS. 10A and 10B</figref> illustrate another embodiment of the present invention for reducing undesired air flow into the inhaler device at its rest position by providing a substantially air-tight seal between the first casing portion and the body portion at the rest position. <figref idrefs="DRAWINGS">FIG. 10A</figref> shows an embodiment of the inhaler device of this embodiment at its rest position that has components substantially similar to those of the inhaler device of <figref idrefs="DRAWINGS">FIG. 2</figref>, such as first casing portion <b>1010</b>, second casing portion <b>1020</b> (including mouthpiece portion <b>1025</b> and body portion <b>1030</b>) and plunger <b>1095</b>. The inhaler device of the embodiment of <figref idrefs="DRAWINGS">FIG. 10A</figref> additionally contains insert element <b>1050</b>.

Portion <b>1090</b> of the inhaler device of <figref idrefs="DRAWINGS">FIG. 10A</figref>, including insert element <b>1050</b>, is shown in exploded view and greater detail in <figref idrefs="DRAWINGS">FIG. 10B</figref>. Insert element <b>1050</b> is receivably and sealably coupled to the distal end of first casing portion <b>1010</b>. For example, in a preferred embodiment, insert element <b>1050</b> is ultrasonically welded to the distal end of first casing portion <b>1010</b>. Additionally, as shown in <figref idrefs="DRAWINGS">FIGS. 10A and 10B</figref>, insert element <b>1050</b> is sealably coupled to body portion <b>1030</b> at the rest position of the inhaler device. For example, the biasing force of the springs in plunger <b>1095</b> may cause a surface of insert element <b>1050</b> to push against a corresponding surface at the distal end of body portion <b>1030</b> at the rest position of the inhaler device, which results in a frictional seal. Such corresponding surfaces on insert element <b>1050</b> and the distal end of body portion <b>1030</b> are normal to the axis of the inhaler device in the embodiment illustrated in <figref idrefs="DRAWINGS">FIGS. 10A and 10B</figref>. Other embodiments will be apparent to those of skill in the art based on the present disclosure; for example, in an embodiment that is converse to the embodiment of <figref idrefs="DRAWINGS">FIGS. 10A and 10B</figref>, insert element <b>1050</b> may be receivably and sealably coupled to the distal end of the body portion. In this embodiment, insert element <b>1050</b> is also sealably coupled to the first casing portion at the rest position of the inhaler device.

While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. For example, the present invention is not limited to the physical arrangements or dimensions illustrated or described. Nor is the present invention limited to any particular design or materials of construction. As such, the breadth and scope of the present invention should not be limited to any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.